e-locker failure

[Wisha Haddan H3]

My e-locker failed on the trail yesterday. It worked at the bottom of the trail, but later when I engaged it the light would blink for 15 secs and then turn off. Tim and I tried every combination we could think of to reset it, but nothing worked. btw this was in 4-lo at a complete stop. And yes I was pushing the right button

There's no message in the DIC and no codes according to onstar. I'll call the dealer after the holiday, but is there anything I can try in the meantime, like disconnecting the battery cable for x minutes? Is there a fuse for the e-locker? I couldn't find one in the fuse box.

[Boar-Ral]

Originally Posted by Wisha Haddan H3

My e-locker failed on the trail yesterday. It worked at the bottom of the trail, but later when I engaged it the light would blink for 15 secs and then turn off. Tim and I tried every combination we could think of to reset it, but nothing worked. btw this was in 4-lo at a complete stop. And yes I was pushing the right button

There's no message in the DIC and no codes according to onstar. I'll call the dealer after the holiday, but is there anything I can try in the meantime, like disconnecting the battery cable for x minutes? Is there a fuse for the e-locker? I couldn't find one in the fuse box.

There is a servo that is responsible for switching modes in the transfer case.* I have heard of incidents where there will be a servo failure, but this is usually reported through the DIC.* It still might be a possibility.

[timgco]

IMO, Don't disconnect your battery. Take it into the dealer. You may have luck and reset everything and it will work a few more times. It's better to let them hook your up your truck to their Tech2 (I think that's what they use) to figure out the issue. That could have been bad if you were in teh rock garden and it failed it there... or on something like radiccal hill.

Mine will be down there next week as well.

Front end alignment and rebalance on one wheel. Other than that, I detailed the whole truck today. Even painted up the UCP and skids.

[NoMoGMPG]

It sounds like the encoder motor is seized, thats the actuator on the t/case where the wires go into. KenP could show you where it is.

[Wisha Haddan H3]

Guess I wasn't clear ... the transfer case is fine. It shifts between 4lo and 4hi locked/unlocked just like butter. It's the rear locking differential that won't engage.

[deserth3]

I'm not an expert but I'd check the wiring going into the diff. There's most likely a connector and it may have come disconnected.
If that don't work take her to the dealer.

[f5fstop]

Originally Posted by deserth3

I'm not an expert but I'd check the wiring going into the diff. There's most likely a connector and it may have come disconnected.
If that don't work take her to the dealer.

Worth a try, but it should set a code (C0388), and turn on the indicator lamp.

It is a simple circuit, the TCCM supplies 12-volts to the rear locker solenoid on the (L-Green wire), and supplies a ground via the black wire to the TCCM. This is also the monitoring circuit. If the TCCM sees the request for axle lockup via the switch, and it energizes the actuator, and no feedback signal is obtained it should set the code.



Wisha Haddan H3:
Try this....
Go back to normal 4-wheel, then bring the vehicle down to less than 3 mph or to a full stop, put the trans in neutral, engage 4-wheel low lock and immediately engage the rear locker. Might work....

[Wisha Haddan H3]

Thanks F5. I tried that and it seemed to work ... at least the light stayed solid this time

I didn't have a chance to really test it tho, so I don't know if it's actually locking the axle. I'll have service check it out this weekend when I use my free oil change.

[f5fstop]

Easy to test, hang one of the wheels off the side of a cliff and see if it turns at the same speed as the other wheel.

I would guess that if the light stays on, it is engaged. The TCCM should turn off the light if not engaged, and flash if it can't engage, then turn it off.

[Boar-Ral]

Originally Posted by f5fstop

Easy to test, hang one of the wheels off the side of a cliff and see if it turns at the same speed as the other wheel.

I would guess that if the light stays on, it is engaged. The TCCM should turn off the light if not engaged, and flash if it can't engage, then turn it off.

Or find a neighbour's new lawn and drive in a tight circle.

[NEOCON1]

this is a good test too

[HummBebe]

Wisha,
If you recall I had the same problem on the Rubcon. Well, BABHUMV took the center panel out and plugged the switch back in, and it worked fine, but the button was still sticky.

The dealer replaced the entire switch panel and now it works great.

Apparently the module behind the switch was bad.

[Wisha Haddan H3]

Originally Posted by HummBebe

Wisha,
If you recall I had the same problem on the Rubcon. Well, BABHUMV took the center panel out and plugged the switch back in, and it worked fine, but the button was still sticky.

The dealer replaced the entire switch panel and now it works great.

Apparently the module behind the switch was bad.

Wonder if I got a bad module too. Thanks bebe, I'll bring it up when I call service

[f5fstop]

Good posibility, in addition, if the center trim panel is ever removed, make sure the connector's lock (blue sliding plastic thingy) is pushed in after the connector is FULLY seated into the module. Not seated, it can cause intermittent problems since it may wiggle a bit.